Development of an automated colorimeter controlled by Raspberry Pi4

Area of Science:

• Analytical Chemistry
• Green Chemistry
• Instrumentation

Background:

• Colorimetric analysis is crucial for food safety and quality control.
• Traditional methods can be time-consuming, resource-intensive, and pose safety risks.
• There is a need for cost-effective, automated, and environmentally friendly analytical tools.

Purpose of the Study:

• To develop and validate a low-cost, automated instrument for colorimetric analysis.
• To assess the instrument's performance using food dye standards and samples.
• To evaluate the device's adherence to green analytical chemistry principles.

Main Methods:

• Construction of a 3D-printed carousel sampler.
• Integration of a Raspberry Pi4-controlled signal measurement module with a TCS34725 color sensor.
• Testing with calibration standards of Tartrazine, Red Allure AC, and Brilliant Blue FCF.
• Analysis of food samples spiked with the tested food dyes.

Main Results:

• The instrument achieved high linearity (R² > 0.995) for food dye quantification.
• Achieved low limits of detection (LOD) for Tartrazine (1.1 μmol L⁻¹), Red Allure AC (1.4 μmol L⁻¹), and Brilliant Blue FCF (0.1 μmol L⁻¹).
• Results were statistically comparable to a conventional benchtop spectrophotometer.

Conclusions:

• The developed instrument provides a cost-effective, automated solution for colorimetric analysis.
• It demonstrates significant reductions in sample volume, waste, and analysis time.
• The device aligns with green analytical chemistry principles, offering safer and more efficient measurements.